Overview
EN ISO 8666:2020 - Small craft - Principal data (ISO 8666:2020) is the harmonized European adoption of the ISO standard that defines principal dimensions, mass specifications and loading conditions for small craft. It applies to recreational and commercial small craft with a length of the hull (LH) up to 24 m. The standard establishes consistent terminology and measurement methods for boat dimensions, masses and standard loading conditions used for design, certification and compliance (including linkage to Directive 2013/53/EU for CE marking).
Key topics
This standard provides authoritative definitions and measurement requirements for:
- Main dimensions: maximum length (Lmax), length of hull (LH), waterline length (LWL), maximum beam (Bmax), beam of hull, waterline beam, depths and midship depth.
- Vertical and clearance data: draught (T), air draught (Ha), freeboard (F), headroom and deadrise angle.
- Areas and volumes: windage area, reference/standard sail areas, total volume (V).
- Mass specifications: net shipping mass, gross shipping mass, light craft mass (mLC), performance test mass (mP), trailer/towed mass (mT), and maximum load (mML) (manufacturer’s recommended maximum load).
- Loading conditions: standardized conditions such as test condition, ready-for-use, fully loaded ready-for-use, empty, light craft, minimum operating and loaded arrival conditions.
- Symbols, units and measurement procedures: harmonized symbols and measurement locations to ensure repeatability across manufacturers and authorities.
Practical applications and users
EN ISO 8666:2020 is used where consistent principal data are required:
- Boat designers and naval architects for specifying hull geometry and mass allocations.
- Manufacturers and boatbuilders to declare principal data on builder’s plates and documentation.
- Certification bodies and notified bodies assessing conformity with Directive 2013/53/EU and assigning design categories.
- Surveyors, importers and dealers for valuation, safety checks and registration.
- Yacht clubs, marinas and owners for operational limits, trailering and handling guidance.
The standard ensures that dimension and mass data used for structural scantlings (EN ISO 12215), stability and buoyancy assessments (EN ISO 12217), cockpit flooding calculations (EN ISO 12216) and load labeling (EN ISO 14946) are consistent and comparable.
Related standards
- EN ISO 12215 (Hull construction/scantlings)
- EN ISO 12217 (Stability and buoyancy requirements)
- EN ISO 12216 (Cockpit drainage/flooding)
- EN ISO 14946 (Manufacturer’s recommended maximum load)
- Directive 2013/53/EU (Recreational craft safety and CE marking)
EN ISO 8666:2020 is essential for consistent small craft principal data, enabling reliable design, certification and regulatory compliance across the EU and internationally.
